There was a technique called Air2Water that was looking for venture capital, I think, several years ago and then distributors The machines were manufactured in Singapore and China under license. I finally gave up on getting one, because they never seemed to get off the ground. They may actually be working now. And now I'm going solar, so it's not feasible for me to have one.
http://www.air2water.com
And yes, Swanny, it's a dehumidification process - but the filtering has to be really intense.
I do like this one, though. And colors! <G>
alys